R33 Gtr Loss Of Boost When On A Long Drive

[Booki]

Will keep you fellas posted, though I am doubtful i will ever find a resolution....due to catching the modification bug

[gotRICE?]

Similar thing happened to my wifes WRX all of a sudden was only running actuator pressure a week later back to the normal 12psi. Suspect the stock solinoid had a fault give yours a good clean out and then send 12v through it an make sure its working

Those stock solenoids in the WRX are a pretty common issue too. Can go either way. My mates one failed on the track. He saw 28psi before he realized and backed off.

Im leaning towards the stock solenoid in this GTR too. See of anyone has one thats been removed they would let you try out?

[dontfeelcold]

I am getting the same things as the OP. I have a R32 GTR with a R33 GTR engine and ecu.

When it happens, I stop. Turn the car off. Turn the car on after 2secs and its back to normal.

Everything is stock except for exhaust and boost restrictor removed. I tried another standard solenoid and had the same problem. The solenoid is normally open at idle then when you apply throttle it switch's off OR its the other way around. I have also tested the solenoid with a 12v power source, its fine. When the fault happens the solenoid no longer changes its state until I turn the car off and turn it on again.

My train of thought is something electrical is putting out a signal that is making the ecu think something is wrong when its an intermittent fault, which explains why when you turn it back on, all is good. I will put some new plugs in, check the coils external physical condition, check the soldering job in the AFM's and check various connectors for bad earths and corrosion.

This seems to be a common problem with GTR's but I haven't been able to find a fix for the problem. The best suggestion was to check earths and for corrosion in plugs.

[Jayden.K]

Do you have heat sheild around your pods, heat soke really can kill power and boost levels, I get more boost when the air and engine is colder, aka more dense air.

[dontfeelcold]

I have a standard air box.

I fixed the problem.

It was the AFM's.

They had been resoldered in the past but 2 joints weren't done very well. So I redid all of them.

Voila! Fixed! Hasn't played up in a week. Before it was doing it every trip, even short ones.

I should mention I changed plugs at the same time as my old ones were worn, and I made sure the coil pack earths were clean, which they still were from last time I cleaned them. But I am pretty sure they had nothing to do with it as the car was running fine before it would drop to low boost.

[ACTIVE-LSD]

I am getting the same things as the OP. I have a R32 GTR with a R33 GTR engine and ecu.

When it happens, I stop. Turn the car off. Turn the car on after 2secs and its back to normal.

Everything is stock except for exhaust and boost restrictor removed. I tried another standard solenoid and had the same problem. The solenoid is normally open at idle then when you apply throttle it switch's off OR its the other way around. I have also tested the solenoid with a 12v power source, its fine. When the fault happens the solenoid no longer changes its state until I turn the car off and turn it on again.

My train of thought is something electrical is putting out a signal that is making the ecu think something is wrong when its an intermittent fault, which explains why when you turn it back on, all is good. I will put some new plugs in, check the coils external physical condition, check the soldering job in the AFM's and check various connectors for bad earths and corrosion.

This seems to be a common problem with GTR's but I haven't been able to find a fix for the problem. The best suggestion was to check earths and for corrosion in plugs.

Sorry to revive a old thread but i have the exact same problem.

This issue is very intermittent and has also occured on my old S15. The way i would describe it is "losing both engine response and boost" only when the car gets hot. mind you my car is 100% stock even with standard airbox. i noticed if i leave car on idle for 2 mins or switch car off it will fix the problem immediately.

I've been trying to diagnose the issue for some time now. first i thought it was due to engine oil, so i switched to 10w-30. then i thought it was fuel injectors so i got those professionally cleaned no. also changed fuel filters, engine coolant temp sensor, 02 sensors and coil packs. NO CHANGE!

So it AFMs the last resort?

[scotty nm35]

It should have been the first resort, it is well known the AFM's require re-soldering occasionally and the dry joints manifest as intermittent power loss as you described. Check the 'how to' tutorial.

[dontfeelcold]

Its the AFM's. Mine started doing the problem again but not as often. The AFM's are old, that's pretty much it.

Need to find someone who can repair these things.

[dontfeelcold]

I found out that if you unplug the water temp sensor (for the ecu, not the gauge) it does the same thing as when the intermittent fault happens so I would recommend changing that plus the air intake temp sensor on the plenum.

[dontfeelcold]

And the problem is still happening. Its rare though now. Change the water and air temp sensors, nothing.

Probably cas, ignitor or AFM getting a glitch. Happens when the air temp is absolutely stinking hot or on a really cold night.

[scotty nm35]

Have you done the suggested re-soldering of the AFM pins yet?

[GTRPSI]

Try the AFM, i didnt believe it was a common issue till i opened my GTR's AFM meters up and found 1 barely connecting and the other one totally not connecting, a few minutes with a knife to remove the cover and some solder brought them back from the dead and fixed my problems.

On the bright side, even if it does not help, you have ensured this problem wont get in your way down the road and cause other issues.

[dontfeelcold]

Yep, I opened up the AFM and resoldered the joints. They looked dry but still attached. The problem went away for a while after doing that but has returned. I'm pull the AFMs out again and resoldering EVERYTHING.